Portable lantern



FIG. 1 is the front elevational view thereof;

FIG. 2 is the rear elevational view thereof;

FIG. 3 is the left side view thereof;

FIG. 4 is the right side view thereof;

FIG. 5 is the top plan view thereof; and,

FIG. 6 is the bottom plan view thereof. 

The ornamental design for a portable lantern, as shown and described. 